1. Technical Field
The invention relates to a method for determining atomic isotope masses in mass spectrometry, atomic isotope ratios being determined from molecular isotope ratios measured by means of an isotope mass spectrometer—ion correction, the determination of the atomic ratios being carried out by setting up and solving a system of equations which describes relationships between the atomic and the molecular ratios, and the system of equations having to have at least as many independent equations as there are atomic ratios.
2. Prior Art
In gas isotope mass spectrometry, gas molecules which are composed of a plurality of different atoms are measured in most cases. In this case, the ratios between various molecular isotope masses are measured. Atomic isotope ratios are mentioned when the mass ratios of two isotopes of a specific atom are to be designated. On the other hand, molecular isotopolog ratios are mentioned when the mass ratios of specific isotopologs at the molecular level are designated.
The determination of molecular isotopolog ratios is usually less desired than the determination of atomic isotope ratios.
In order to determine the atomic ratios from the molecular isotopolog ratios, it is known to set up various equations which describe theoretical and empirical relationships between the respective ratios. These equations are then solved individually and in a complicated manner for the atomic ratios sought and under certain circumstances each individual equation is solved numerically. If, during a further isotope mass measurement, other atoms or molecules play a part, new equations have to be set up and these in turn have to be solved individually. These steps have to be carried out independently for each type of gas which is measured or is to be measured.